Detection of Mechanical Deformation in Old Aged Power Transformer Using Cross Correlation Co-Efficient Analysis Method

Detection of minor faults in power transformer active part is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. Sweep Frequency Response Analysis (SFRA) is an effective low-voltage, off-line diagnostic tool used for finding out any possible winding displacement or mechanical deterioration inside the Transformer, due to large electromechanical forces occurring from the fault currents or due to Transformer transportation and relocation. In this method, the frequency response of a transformer is taken both at manufacturing industry and concern site. Then both the response is compared to predict the fault taken place in active part. But in old aged transformers, the primary reference response is unavailable. So Cross Correlation Co-Efficient (CCF) measurement technique can be a vital process for fault detection in these transformers. In this paper, theoretical background of SFRA technique has been elaborated and through several case studies, the effectiveness of CCF parameter for fault detection has been represented.

Optimal Scheduling Strategy of Source-Load-Storage Based onWind Power Absorption Benefit

In recent years,the proportion of installed wind power in the three north regions where wind power bases are concentrated is increasing,but the peak regulation capacity of the power grid in the three north regions of China is limited,resulting in insufficient local wind power consumption capacity.Therefore,this paper proposes a two-layer optimal scheduling strategy based on wind power consumption benefits to improve the power grid’s wind power consumption capacity.The objective of the uppermodel is tominimize the peak-valley difference of the systemload,which ismainly to optimize the system load by using the demand response resources,and to reduce the peak-valley difference of the system load to improve the peak load regulation capacity of the grid.The lower scheduling model is aimed at maximizing the system operation benefit,and the scheduling model is selected based on the rolling schedulingmethod.The load-side schedulingmodel needs to reallocate the absorbed wind power according to the response speed,absorption benefit,and curtailment penalty cost of the two DR dispatching resources.Finally,the measured data of a power grid are simulated by MATLAB,and the results show that:the proposed strategy can improve the power grid’s wind power consumption capacity and get a large wind power consumption benefit.

Power system stabilizer design using hybrid multi-objective particle swarm optimization with chaos

A novel technique for the optimal tuning of power system stabilizer (PSS) was proposed,by integrating the modified particle swarm optimization (MPSO) with the chaos (MPSOC).Firstly,a modification in the particle swarm optimization (PSO) was made by introducing passive congregation (PC).It helps each swarm member in receiving a multitude of information from other members and thus decreases the possibility of a failed attempt at detection or a meaningless search.Secondly,the MPSO and chaos were hybridized (MPSOC) to improve the global searching capability and prevent the premature convergence due to local minima.The robustness of the proposed PSS tuning technique was verified on a multi-machine power system under different operating conditions.The performance of the proposed MPSOC was compared to the MPSO,PSO and GA through eigenvalue analysis,nonlinear time-domain simulation and statistical tests.Eigenvalue analysis shows acceptable damping of the low-frequency modes and time domain simulations also show that the oscillations of synchronous machines can be rapidly damped for power systems with the proposed PSSs.The results show that the presented algorithm has a faster convergence rate with higher degree of accuracy than the GA,PSO and MPSO.

Identity Transformation of China through the Anti-Monopoly Law Penalty on Japanese Automotive Parts and Bearings Enterprises

The identity transformation of China is analyzed through the legal punishment given by China＇s National Development and Reform Commission on Japanese automotive parts and bearings enterprises that broke China＇s Monopoly Law by price- fixing in the automotive parts market of China for more than ten years. The standards for illegal conduction this penalty based are the international Cartel rules, the specific legal procedure is beyond the main concern of this study so the obscurity of how this penalty decided is kept aside for the sake of respecting the painstaking labor fruits of relevant executive departments as well as for dispensing political sensitivity related to any academic analysis developed. Three Japanese newspaper reports concerning this penalty fine are selected for critical discourse analysis. Emotional ambience of them is derogative, neutral, and approving respectively. Foucault＇s triad relationship of discourse-power-identity is borrowed and the postmodernists＇ view of the ＂other＂ is corroborated with the self-presentation of China. Positive self-presentation is underscored by the contrast of negative other-presentation and vice versa, the negative commendation on this punishment event revealed in certain news coverage is to lessen the negative image of Japanese enterprises because of their shared Japanese identity. However their fundamental tone maybe, the fact that China evolves to be able to handle the illegal international events in its confines with dignity is tacitly recognized as a warning in three newspapers. The new identity of China is thus highlighted as the role of the other by the Japanese media. The reason why Japanese accept it instead of staging substantial resistance is analyzed from the Japanese cultural considerations of the hierarchical sequence or the ＂weizhiyishi＂ （positional consciousness or postural consciousness）, and the practical reasons of why Hitachi and Nachi commit self-confession is analyzed. All these responses from Japanese side are the manifestation of China＇s being in charge of the situation, it has the ball at its feet in this power gaming.

考虑灵活爬坡辅助服务和弃风惩罚的现货电能量市场出清模型

为解决风电不确定性引起的系统爬坡能力不足、高比例风电接入时系统总运营成本偏高等问题,提出了计及改进灵活爬坡辅助服务和弃风惩罚的现货电能量市场出清模型。首先,分析了单台机组在出力状态、投入/退出过程中需要满足的爬坡速率约束,以及系统因净负荷波动需要满足的爬坡能力约束,提出了改进的灵活爬坡辅助服务产品。然后,以发电计划和机组状态为决策变量,构建了计及灵活爬坡辅助服务和弃风惩罚的目标函数。最后,通过两个算例从风电预测误差、风电渗透率和弃风惩罚成本等不同角度进行深入分析,验证所提出清模型的有效性。算例结果表明,所提出清模型既提高了系统运行的灵活性和经济性,又提升了高比例风电的消纳能力。

风光储联合发电站与电力用户的电能直接交易模型

随着可再生能源和负荷预测精度的不断提升,风光储联合发电站和电力用户之间的电能直接交易具有了可行性。文章建立了风光储电站和电力用户之间电能直接交易的消纳模型。该模型以社会总效益最大化为目标,在传统模型的基础上,加入直购电合同中的电功率约束和储能相关运行约束,同时对于签订的总合同电量约束做出调整,并加入过网费和削减合同,惩罚权衡直购电量给系统带来的综合效益。结合生成的场景聚类,通过算例分析了风光储电站的日前优化结果,研究了合同电量限制因子、惩罚因子对直购电量和总社会经济效益的影响,结合纳什议价模型分析直购电价对利润均衡度的影响,验证了模型的实用性与有效性。

地方性法规增设行政处罚的规范基础

法律、行政法规对某一抽象事项已有规定时,地方性法规就具体事项增设行政处罚,包括完整增设与补充增设两种类型。对之进行合法性判断时,应根据地方性法规的规范效力推定立法行为合法,采取合法性推定的教义学方法。《立法法》第82条第1款第2项与《行政处罚法》第12条第1款共同构成地方性法规增设行政处罚的授权基础。《行政处罚法》第12条第3款无法支持地方性法规完整增设行政处罚,也不构成对地方性法规补充增设行政处罚的独立授权。地方性法规增设行政处罚,在不违反消极限制的同时,还应符合积极要件。地方性事务标准是地方性法规增设行政处罚的唯一积极要件,可从纵、横两个维度展开,区分为治理对象特殊性、区域特征差异性与治理能力差异性三个子标准。

基于改进混沌算法的供热机组热电负荷优化分配系统

热电负荷拟合效果不佳会导致供热机组实际耗能量大幅增加,为此,该文设计基于改进混沌算法的供热机组热电负荷优化分配系统。按照主供热单元连接形式,实现热电负荷循环模式规划,确定热电负荷优化布置标准。根据混沌指数计算结果,求解改进罚函数,完成对混沌算法的改进,构建供热机组热电负荷分配的数学模型,并设计负荷分配模型的约束条件,完成供热机组热电负荷优化分配系统设计。实验结果表明,热电负荷参量与标准拟合曲线之间的误差不会超过30%,可以解决因热电负荷拟合效果不佳导致的供热机组实际耗能量增加的问题。

教育行政处罚的设定权探究

教育行政处罚设定权作为一项立法权,其权力来源由宪法、法律、法规以及规章进行严格限制,但在立法与司法实践过程中,教育行政处罚设定权存在超出立法限制而受到合法性质疑的情况。为了达到教育行政处罚设定权规范化的目的,需要从教育立法系统性、法律位阶调整以及事后评估三方面对教育行政处罚设定权进行规范,从而进一步完善我国教育法律体系建设。

行政处罚权下沉制度的问题检视及其完善路径

新《行政处罚法》第二十四条在立法层面上确立了行政处罚权下沉制度的重要地位。当前行政处罚下沉制度暴露出下沉决定主体和方式不明、下沉内容范围与边界模糊、下沉对象承接能力判断标准偏差以及监督实际效果不佳等问题。综合基层执法现实考量,应当明确以授权论为中心的双轨模式,通过动态权力清单的形式把握行政处罚权力下沉的内容边界,以过程性视角对基层行政机关能否有效承接行政处罚权做出判断,并致力于通过内外协同监督的方式实现对基层行政执法的有效监督,以期发挥出基层行政机关治理的最大效能。

证券交易所收取惩罚性违约金:制度争议与理论回应

作为证券交易所重要的财产性惩戒措施,惩罚性违约金长期未得应用,客观上限制了交易所自律监管的可用措施和惩戒力度。推动制度落地需要着力弥平三方面集中争议:一是关于法律性质的争议。从权利来源及实践效果综合分析,交易所收取的惩罚性违约金应界定为私法上之违约金而非公法上之罚款,特别权力关系理论及重要性理论为此提供了额外的解释路径。二是对是否必要以及能否实现过罚相当的质疑。基于私法上之违约金的性质以及自律监管的特殊性,惩罚性违约金与行政罚款不构成重复处罚亦无需折抵,在时效性、覆盖范围等方面与先行赔付等行政执法机制存在明显差异,具有独特价值。具体金额宜沿用定额标准并优化区间设置,在过重与过轻之间寻求平衡。三是关于可执行性的争议。可采“公力+私力”救济的二元结构设置执行保障措施,并依托交易所风险基金及投资者保护基金将违约金用于投资者保护领域。

计及风电出力惩罚成本的电力系统经济调度

风电出力具有随机性和间歇性的特点,如何在经济调度模型中处理大型并网风电场模型是长期以来关注的热点。为此,引入高估出力期望、低估出力期望以及惩罚成本系数的概念,在此基础上,提出了计及风电出力惩罚成本的电力系统经济调度模型。通过在目标函数中引入惩罚成本,使优化结果兼顾了风能的利用率和总经济成本。算例结果验证了该方法的有效性。

牛顿最优潮流算法中离散控制量的新处理方法

提出了一种新的基于正曲率二次罚函数的最优潮流算法中离散控制量的处理方法。该方法利用二次罚函数产生的虚拟费用迫使离散控制到达它的一个分级上，引入机制简单有效，并能很好地结合在牛顿最优潮流算法中。文中对一个IEEE试验电力系统和两个中国的实际电力系统做了数值计算。结果表明，该方法有良好的收敛性、精确性，具有很强的实用意义。

平抑机组出力波动的发电计划模型及其应用

在编制基于发电成本最小的发电计划时,机组出力曲线经常会出现来回波动的情况。针对这一问题,引入了机组出力变化惩罚因子,并根据不同容量机组的生产特性,分别建立了机组出力变化的线性惩罚模型和分段惩罚模型。采用某省级电力系统算例对所建立的模型进行测试。算例结果表明,模型能有效平抑大中型机组的出力波动,保证出力平稳;在一定程度上可以改善小型机组的出力特性,便于在实际中进行控制;满足电网安全约束,保证安全断面不越限。

一种基于高斯罚函数的大规模无功优化离散变量处理方法

含离散变量的电力系统无功优化属于非线性混合整数规划问题,这类问题目前仍缺乏理论上严格有效的求解方法。提出一种基于高斯罚函数的离散变量连续化的处理策略,用于求解含离散变量的无功优化问题。在对高斯罚函数的性质和参数影响进行分析讨论后,设计出一种结合非线性规划内点法和高斯罚函数参数调整策略的无功优化实用算法。由于高斯罚函数具有连续可微等良好性质,所提方法具有良好的寻优化和计算性能。最后在不同规模的标准系统和实际系统上进行算例测试,以验证算法的鲁棒性和实用性。

基于遗传算法的动力配煤模型

遗传算法作为一种函数优化方法,不依赖于求解问题的本身,利用简单的编码技术和繁殖机制,快速有效地搜索复杂、高度非线性和多维空间,寻求最优解.动力配煤是一个多元优化问题,混煤与各组成单煤间的非线性关系增加了约束条件向确定性方程转化的难度.将遗传算法用于动力配煤方案优化,利用其全局性、并行性、快速性的特点,有效地解决了配煤中的非线性多约束问题,取得了理想的效果.

基于动态调峰裕度的风电并网协调优化调度

风电并网增加了系统有功调度的难度,为了协调系统运行的可靠性、经济性与风电利用效益之间的矛盾,提出了24点调峰裕度指标,从调峰的角度确定出系统动态正负旋转备用和风电并网功率,并构建了以系统总运行成本最小为目标,含水、火电运行价格成本、风电弃风惩罚成本以及系统备用惩罚成本的风电并网协调优化调度模型。针对该模型,采用优先顺序法和改进粒子群算法,并基于某个含风电的区域电网算例进行仿真验证。结果表明,所提出的指标和优化模型为解决风电并网运行问题提供了一种有效方法。

风光互补独立供电系统的优化设计

在设计风光互补独立供电系统时,系统中需要优化的不仅有光伏电池和蓄电池的容量,还应该有风力发电机种类和容量以及光伏电池的倾角。优化目标为系统安装成本,约束条件为供电可靠性,其指标负载缺电率LP- SP需经仿真运行得到。本问题属于非线性整数规划,也是一个NP-hard问题。用包含精英策略的遗传算法优化,以自适应罚函数法处理约束。计算和验证表明本文采用的算法收敛,能同时优化风力发电机类型和容量、光伏电池的容量和倾角以及蓄电池的容量,并且计算效率高。

含风电安全约束机组组合的旋转备用优化

风电的随机性会对发电计划带来较大影响,因此研究含风电场的发电计划很有必要。首先研究了含风电场的安全约束机组组合问题,通过优化常规火电机组出力与备用,并对处于一定置信区间内的风电出力进行合理的取值安排,实现动态经济调度;再在优化模型的目标函数中对正负旋转备用单独计费引入了惩罚费用,以应对风力预测误差给系统调度带来的影响;最后在网络安全约束方面,采用直流潮流模型,使用转移因子,并使用CPLEX求解。实例验证表明该方法准确高效,所提出的调度模型合理,算法具有较好的工程实用价值。

改进最优潮流牛顿算法有效性的对策研究

对最优潮流牛顿算法实际应用中的两个主要困难：数值不稳定性和如何快速正确地预估起作用的不等式约束集分别作了详尽的分析研究，并提出了相应的处理对策。包括：一种改进的软惩罚方案；一种根据电网拓扑结构的快速预估起作用的电压不等式约束集的方案；试验迭代的有限次终止方案等等。并对多个ＩＥＥＥ 试验电力系统和我国２ 个实际电力系统作了全面的数值计算。结果表明，上述改进措施和方案，显著地提高了牛顿ＯＰＦ算法的数值稳定性、收敛性和计算速度，具有实用意义。